Apparent Homozygosity for a gr/gr AZFc Deletion in A 47,XYY Man with Oligozoospermia and Secondary Infertility.

Background: Approximately 1 in 1000 men have a 47,XYY karyotype. Previous publications have presented cases of infertile XYY men and have suggested that the additional Y chromosome may cause disrupted meiosis leading to sperm apoptosis. The purpose of the current study was to determine whether XYY men are over-represented in infertility cohorts.

Identifying susceptibility genes for primary ovarian insufficiency on the high-risk genetic background of a fragile X premutation.

Objective: To identify modifying genes that explains the risk of fragile X-associated primary ovarian insufficiency (FXPOI).

Design: Gene-based, case/control association study, followed by a functional screen of highly ranked genes using a Drosophila model.

Setting: Participants were recruited from academic and clinical settings.

Development of Genetic Testing for Fragile X Syndrome and Associated Disorders, and Estimates of the Prevalence of FMR1 Expansion Mutations.

The identification of a trinucleotide (CGG) expansion as the chief mechanism of mutation in Fragile X syndrome in 1991 heralded a new chapter in molecular diagnostic genetics and generated a new perspective on mutational mechanisms in human genetic disease, which rapidly became a central paradigm ("dynamic mutation") as more and more of the common hereditary neurodevelopmental disorders were ascribed to this novel class of mutation. The progressive expansion of a CGG repeat in the gene from "premutation" to "full mutation" provided an explanation for the "Sherman paradox," just as similar expansion mechanisms in other genes explained the phenomenon of "anticipation" in their pathogenesis. Later, premutations were unexpectedly found associated with two other distinct phenotypes: primary ovarian insufficiency and tremor-ataxia syndrome.

Multiplex families with epilepsy: Success of clinical and molecular genetic characterization.

Objective: To analyze the clinical syndromes and inheritance patterns of multiplex families with epilepsy toward the ultimate aim of uncovering the underlying molecular genetic basis.

Methods: Following the referral of families with 2 or more relatives with epilepsy, individuals were classified into epilepsy syndromes. Families were classified into syndromes where at least 2 family members had a specific diagnosis.

Population-based estimates of the prevalence of FMR1 expansion mutations in women with early menopause and primary ovarian insufficiency.

Purpose: Primary ovarian insufficiency before the age of 40 years affects 1% of the female population and is characterized by permanent cessation of menstruation. Genetic causes include FMR1 expansion mutations. Previous studies have estimated mutation prevalence in clinical referrals for primary ovarian insufficiency, but these are likely to be biased as compared with cases in the general population.

Intermediate sized CGG repeats are not a common cause of idiopathic premature ovarian failure.

Background: It is recognized that FMR1 premutation expansions are associated with premature ovarian failure (POF), but the role of smaller repeats at the boundary of premutation and normal is less clear.

Methods: We have therefore investigated the incidence of these intermediate sized FMR1 CGG repeats (35-58 repeats) in a series of 366 women ascertained because of menopause before the age of 40.

Results: We found no significant difference in the incidence of intermediates in cases compared with controls.